Wire wrapping head



Feb. 17, 1970 J. O. ETCHISON. JR. ET AL WIRE WRAP? I NG HEAD 2Sheets-Sheet 1 Original Filed Oct. 3. 1963 Feb. 17, 1970 J. o. ETCHISON.JR; ETAL Re. 26,791

WIRE WRAPPING HEAD 2 Sheets-Sheet 2 Jriginal Filed Oct. 5. 1963 UnitedStates Patcnt O 26,791 WIRE WRAPPING HEAD John 0. Etchison, Jr.,Clemmons, and Jack C. Hetherington, Greensboro, N.C., assignors toWestern Electric Company, Incorporated, New York, N.Y., a corporation ofNew York Original No. 3,246,381, dated Apr. 19, 1966, Ser. No. 313,706,Oct. 3, 1963. Application for reissue Apr. 18, 1968, Ser. No. 724,325

Int. Cl. H01r 43/00; 1101b 13/00; B21f 3/00 U.S. Cl. 29-203 9 ClaimsMatter enclosed in heavy brackets appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE A wire wrapping bit has an elongated sleevemember and an elongated spindle slidably mounted within the sleeve forreceiving an end of a wire and wrapping the end of the wire is receivedand fully encompassed by a in a longitudinal bore in the tip of thespindle and the end of the wire is received and fully encompassed by atransverse slot formed through the spindle. When the end of the sleeveis moved relative to the slot toward the tip of the spindle, the end ofthe wire is captured in a longitudinal passageway formed between thesleeve and spindle.

This invention relates to a [dual] wire wrapping head and moreparticularly to a [dual] wire wrapping head for [simultaneously]wrapping a wire strand onto a [pair of] tcrminal[s to interconnect theterminals] to make an electrical connection thereto.

In the manufacture of electrical units, it is often necessary tointerconnect terminals extending from the units. For example, in themanufacture of electrical units such as printed circuit boards,telephone terminal boards, and the like, it may be necessary toelectrically interconnect two terminals extending from the units. Thismay be accomplished by wrapping the stripped ends of a measured lengthof insulated wire strand onto the terminals to form wrapped connectionsthereon and electrically interconnect the terminals. It is economicallydesirable to perform such a cycle of operation at high speeds.

Throughout the remainder of the specification, the terms hookup lead,"and lead, are indicative of a broad class of strand-like articles whichincludes insulated or bare wire strand, insulated or bare stranded wire,and the like.

One prior art apparatus for simultaneously forming wrapped connectionson a pair of terminals includes a pair of wiring tools mounted on arotary drive. Each Wiring tool includes a generally cylindrical spindlehaving a reduced diameter shank portion and a wrapping head which isprovided with a hook-like device for gripping an end of a length ofhookup lead. The spindle is mounted for axial movement within a tubularsleeve.

In the operation of this prior art apparatus, a measured length ofhookup lead is laid unconfined across the shank portion of the spindles.The spindles are retracted within the sleeves and the hook-like devicesof the wrapping heads grip the lead and cooperate with the sleeves tostrip the insulation from the ends of the lead. The wiring tools arethen advanced onto the terminals and simultaneously rotated in oppositedirections to wrap the stripped ends of the hookup lead onto theterminals and form Wrapped connections thereon to electricallyinterconnect the terminals.

A hookup lead having fine, flexible, wire strand is normally used toform wrapped connections to interconnect Re. 26,791 Reissued Feb. 17,1970 terminals on these electrical units. When such a hookup lead islaid unconfined upon the shank portion of the spindles of the prior artapparatus, it is subject to vibration of the apparatus air currents, anda variety of forces tending to dislodge the hookup lead and interruptthe cycle of operation. This interruption results in inefliciency,product spoilage, and economic loss.

The apparatus of this invention provides facilities for overcoming theseand other problems associated with the prior apparatus. Moreparticularly, provisions are made in the [dual] wire wrapping head ofthe invention for precluding a length of hookup lead from beingdislodged from the [dual] wire wrapping head prior to the wrapping of[the] a terminal[s].

Testing of the novel [dual] wire wrapping head revealed that the devicesassociated with the prior art apparatus for feeding a measured length ofhookup lead to the [dual] wire wrapping head were inadequate. Therefore,a new device has been provided which cooperates with the instant [dual]wire wrapping head in a novel manner to achieve improved measuring,severing, and precise feeding of a measured length of hookup lead to thefacilities which preclude the hookup lead from being dislodged from the[dual] wire wrapping head prior to wrapping of [the] a terminal[s].

An object of this invention is to provide a new and improved [dual] wirewrapping head.

Another object is to provide a new and improved dual wire wrapping headfor simultaneously wrapping wire strand onto a pair of terminals tointerconnect the terminals.

Another object is to provide a new and improved dual wire wrapping headwherein the stripped ends of a predetermined length of hookup lead aresimultaneously wrapped onto a pair of terminals to interconnect theterminals with insulated wire strand thercbetween.

Another object is to provide a new and improved [dual] wire wrappinghead for [simultaneously] wrapping the end[s] of a measured length ofhookup lead onto a [pair of] terminal[s] wherein insulation s strippedfrom the end[s] of the hookup lead during the wrapping operation.

Another object is to provide a [dual] wire wrapping head for[simultaneously] wrapping the stripped end[s] of a measured length ofhookup lead onto a [pair of] terminal[s] wherein the hookup lead isprecluded from being dislodged from the [dual] wire wrapping head priorto the wrapping of the terminal[s].

Another object is to provide facilities for accurately measuring,severing, and precisely feeding a measured length of hookup lead to thefacilities of the [dual] wire Wrapping head which preclude the hookuplead from being dislodged prior to the wrapping of the tcrminal[s].

With these and other objects in view, a [dual] wire wrapping headillustrating certain features of the invention includes a [pair of]bit[s] having facilities for receiving a [pair of] terminal[s], forprecluding a measured length of hookup lead from being dislodged fromthe [dual] wire wrapping head prior to a wrapping operation, and forconfining the stripped end[s] to guide the lead during a wrappingoperation.

In a specific embodiment of this [dual] wire wrapping head, each bitincludes a spindle concentrically mounted within a sleeve. Each spindleis P ovided with a terminal receiving bore in the end of the spindle, atransverse guide slot through which the length of hookup lead passes forprecluding the lead from being dislodged prior to the wrappingoperation, and a longitudinal groove. Each sleeve is provided with anelongated passage which cooperates with the longitudinal groove of itsassociated spindle for stripping insulation from an end of the leadduring the wrapping operation and for confining the stripped end toguide the lead during the wrapping operation.

Other objects and advantages of the invention will become apparent froma consideration of the detailed specification and the accompanyingdrawings, wherein:

FIG. 1 is an end view of a pair of bits of a dual wire wrapping headembodying certain principles of the invention, each bit including aspindle mounted concentrically within a sleeve, each spindle having atransverse guide slot and a longitudinal groove, and each sleeve havingan elongated passage;

FIG. 2 is a sectional view taken along the line 2-2 of FIG. 1 with theaddition of a length of hookup lead passing through the transverse guideslots of the spindles;

FIG. 3 is a view similar to FIG. 2 showing the spindles retracted withinthe sleeves;

FIG. 4 is a view showing a pair of terminals electrically interconnectedby a length of hookup lead;

FIG. 5 is a side view taken along the line 55 of FIG. 1 showing thetransverse guide slot and longitudinal groove of one of the spindles;

FIG. 6 is a perspective view of one of the bits showing the lead passingthrough the transverse guide slot of the spindle;

FIG. 7 is a perspective view of one of the bits showing a cutting edgeof the longitudinal groove of the spindle and a cutting edge of theelongated passage of the sleeve;

FIG. 8 is a front view partially in section showing facilities forfeeding a predetermined length of hookup lead through the transverseguide slots of the spindles; and

FIG. 9 is a view showing the wire feeding facilities projecting apredetermined length of hookup lead through the transverse guide slotsof the spindles.

Referring to FIG. 4, there is shown an electrical unit 12 such as aprinted circuit board, a telephone terminal block, or the like. having apair of conventional terminals 13 and 14 extending from a base 16 of theunit. Terminals 13 and 14 are mechanically and electricallyinterconnected by a measured length of hookup lead 17 (shown in FIG. 2).Leads 17 comprises an electrically conductive fine gauge, flexible wirestrand l8 and a covering of insulation 19.

Referring to FIGS. 1, 2 and 3, a pair of bits 27 and 28 of the dual wirewrapping head includes spindles 29 and 31 slidably movable withinsleeves 33 and 34. Since bits 27 and 28 are identical in construction,only hit 27 will be described. Spindle 29 has an axial, longitudinally,extending terminal receiving bore 36 and a longitudinal groove 37 ofsemi-circular cross section on the side of the tip portion of thespindle. Groove 37 has a diameter substantially equal to the diameter ofwire strand 18.

A transverse guide slot 38 extends through spindle 29 and intersects thelongitudinal axis of groove 37. As best seen in FIG. 5. guide slot 38tapers to provide a connection between the guide slot and groove 37.Groove 37 curves about the end of spindle 29 to meet terminal receivingbore 36.

The end geometry of spindle 29 is identical to that of a spindleinvented by Messrs. J. O. Etchison and J. C. Hetherington and isdisclosed in copending application for patent, [serial number 230,759]Patent No. 3,213,894, which is assigned to the same assignee as thisapplication. That application teaches that when a wire strand is wrappedaround a terminal, the wire strand naturally assumes an arcuate pathwhich has a predetermined radius of bend, referred to in the aboveapplication as the natural bending radius. The ends of grooves 37 of thespindles of this application are conformed to the natural bending radiusas taught in the copending application.

Sleeve 33 is mounted over spindle 29 and is accurately machined toprovide a slidable metal-to-metal fit between the sleeve and spindle.Sleeve 33 has a cutout portion 41 extending from the end of the sleeveto a point beyond guide slot 38 when spindle 29 is extended as shown inFIG. 2. An elongated passage 42 (FIGS. 2 and 3), of semi-circular crosssection and having a diameter equal to the diameter of wire strand 18.is formed axially and longitudinally along the inner surface of sleeve33. Passage 42 extends from the end of sleeve 33 to a point beyond theupper end of groove 37 when the end spindle 29 and the sleeve are flushas shown in FIG. 3.

Passage 42 is opposite and aligned with groove 37 and together thepassage and groove form a guideway 43 equal to the diameter of wirestrand 18. An elongated longitudinally extending channel 44 is formedthrough sleeve 33. A pin 46 is firmly fixed to spindle 29 and is mountedfor slidable movement within channel 44. Pin 46 permits relativelongitudinal movement, but prevents relative rotational movement, of thespindle and sleeve.

Bits 27 and 28 are mounted in a conventional machine (not shown andforming no part of this invention) for moving the spindles within andout of the sleeves and for simultaneously rotating the bits in oppositedirections, for example, the Automatic Wire-Wrap" Machines Models 14Fand 141 produced by the Gardner- Denver Company of Grand Haven, Mich.

In FIGS. 5, 6. and 7, there is shown in detail guide slot 38 formed inspindle 29. Guide slot 38 tapers down to a neck 51 (FIGS. 5 and 7) whichhas a diameter equal to that of hookup lead 17. Neck S1 narrows down tothe diameter of wire strand 18 at the entrance to groove 37. Groove 37is provided with a cutting edge 52 at the point where neck 51 meets thegroove. Sleeve 33 is provided with a cutting. edge 53 at the end ofpassage 42 at the tip of. the sleeve (FIGS. 2 and 7).

Referring to FIG. 8, wire feed apparatus 54 (shown in block outline inFIG. 2) includes a hollow wire guide tube 61 having a needle portion 62and an enlarged cylindrical portion 63. Cylindrical portion 63 isprovidcd with a stop collar 64 and is mounted for slidable movementwithin a sleeve 66. Sleeve 66 is provided with a stop collar 67 and ismounted on a gripper block 68. A compression spring 69 is confinedbetween collars 64 and 67 and urges wire guide tube 61 to the right withrespect to sleeve 66, shown in FIG. 8. A pin is mounted on sleeve 66 andextends into a channel 70 formed in cylindrical portion 63 to preventspring 69 from projecting guide tube 61 out of the sleeve.

Gripper block 68 includes a cylinder 71 containing a piston 72 with aplunger 73 attached thereto. A guide channel 75 passes through gripperblock 68 and is aligned with the passage within wire guide tube 61.Pressurized fluid may be introduced into cylinder 71 through fitting 76.

A piston 77 is contained within a double acting cylinder 78 and isconnected to a piston rod 79 which is attached to a lug 81 mounted ongripper block 68. Pressurized fluid may be introduced alternatively intoeither end of double acing cylinder 77 through fittings 82 and 83.

A cutting assembly 66 (shown in outline) includes a pair of cuttingblades 87 and 88 which are actuated through a set of gears (shown inoutline) by a piston rod 91 connected to a piston 89 within a cylinder92. Pressurized fiuid may be introduced into cylinder 92 through afitting 93. It will be obvious to one skilled in this art that thepressurized fluid cylinders could readily be replaced with anappropriate system of electrically operated solenoids, or otherappropriate systems.

OPERATION OF WIRE FEED APPARATUS In FIGS. 8 and 9, there are shown inoutline form the pair of spindles 29 and 31 having aligned transverseguide slots 38. In FIG. 8, the wire feed apparatus is shown in readinessfor a cycle of operation. Pressurized fluid is introduced throughfitting 76 to drive plunger 73 into locking engagement with anindeterminate length of hookup lead 17 being fed from a supply 99.

Pressurized fluid is then introduced through fitting 82 intodouble-acting cylinder 78 to drive piston 77 to the right. This actionmoves gripper block 68 with lead 17, sleeve 66, and wire guide tube 61to the right until collar 64 engages a wall of cutting assembly 86.Gripper block 68 with lead 17 and sleeve 66 continue to move to theright until the position shown in FIG. 9 is attained.

In this manner, needle portion 62 is projected through guide slot 38 ofspindle 29 (FIG. 9) and stops just short of spindle 31. Lead 17 isprojected beyond the end of needle potion 62 and through guide slot 38of spindle 31. Spindle 31 is then withdrawn into sleeve 34 to hold lead17 in place.

Pressurized fluid is evacuated from cylinder 71 to disengage plunger 73from lead 17. Pressurized fluid is introduced through fitting 83 intodouble-acting cylinder 78 to drive piston 77 back to its initialposition (FIG. 8). This action moves gripper block 68 and wire guidetube 61 to their initial starting positions (FIG. 8). During thismovement, lead 17 is held in place by spindle 31 and sleeve 34.Pressurized fluid is then introduced through fitting 93 into cylinder 92to actuate cutting blades 87 and 88 to sever lead 17 and leave ameasured length extending through guide 38 of spindles 29 and 31.

OPERATION OF DUAL WIRE WRAPPING HEAD Referring to FIGS. 14, after wirefeed apparatus 54 has severed and projected predetermined length of lead17 through guide slots 38 of spindles 29 and 31, the lead rests in theguide slots of the spindles (FIGS. 2 and 6). Lead 17 is positivelyprecluded from being dislodged from the dual wire wrapping head due tovibration, air currents, retraction of the spindles into the sleeves, orfor other like reasons, by guide slots 38 which completely surround thelead.

Spindle 29 is retracted until it reaches the partially retractedposition of spindle 31 and then both spindles are fully retracted withinsleeves 33 and 34, respectively.

It will be apparent to one skilled in this art that spindle 31 couldalso be fully retracted within sleeve 34 (as shown in FIG. 3) and thenspindle 29 could be retracted within sleeve 33.

As the spindles are being retracted, cutting edges 52 of grooves 37 andcutting edges 53 of passages 42 become aligned and peripherally severinsulation 19 of lead 17 at points 101 (FIG. 3). The spindles continueto be retracted until the ends of the spindles are flush with the endsof the sleeves. As noted above, groove 37 and passage 42 define aguideway 43 having a diameter substantially equal to the diameter ofwire strand 18. Therefore, as the spindles are retracted within thesleeves, cutting edges 52 of grooves 37 cooperate with passages 42 tostrip portions 102 (FIG. 3) of insulation 19 from the ends of themeasured length of lead 17.

In FIG. 3, spindles 29 and 31 are shown -fully retracted within sleeves31 and 33. A length of lead 103 extends between bits 27 and 28. Asection 106 of wire strand 18 is confined in each guideway 43 formed bygroove 37 and passage 42. Portions 102 of insulation 19 have beenstripped from the ends of lead 17.

Bits 27 and 28 are then advanced so that terminals 13 and 14 arereceived within terminal receiving bores 36 of the spindles. Bits 27 and28 are then simultaneously rotated in opposite directions to formwrapped connections 107 and 108 on terminals 13 and 14 (FIG. 4). Duringthe wrapping operation wire strand 18 of hookup lead 17 is pulledthrough guideways 43 and portions 102 of insulation 19 are stripped fromthe ends of the lead.

Control of the sequence of operations of the wire feed apparatus anddual wire wrapping head may be accomplished in a number of conventionalways, for example a punched tape system may be used for directing thevarious steps of the operations described. Another arrangement may use asystem of switches and solenoids whose sequence is controlled by a camsystem and a motor driven cam shaft.

It will be obvious to one skilled in this art that bare wire strandcould be used in place of hookup lead in a given application and that nomodification of the dual wire wrapping head described would benecessary. It will be understood that the apparatus described is merelyillustrative of the principles of this invention and that otherembodiments may be devised Without departing from the scope of theinvention.

What is claimed is:

[1. A dual wire Wrapping head for interconnecting terminals with hookuplead, comprising a pair of wrapping bits, each bit having means thereonfor engaging a terminal, means for guiding hookup lead about theterminal, and a guide slot formed transversely through the bit forreceiving and for fully encompassing a length of hookup lead projectedthrough the guide slot.]

2. A [dual] wire wrapping head for interconnecting terminals with hookuplead including a [pair of] wrapping [bits, each] bit comprising anelongated sleeve member, [and] an elongated spindle slidably mountedwithin the sleeve and having means thereon for [engaging] receiving aterminal [and means for guiding hookup lead about a terminal], thespindle having a guide slot passing transversely [therethrough] 10 thelongitudinal axis of the spindle for receiving and completelysurrounding a length of hookup lead projected therethrough inpreparation for wrapping about the terminal, and

a longitudinal passageway formed between the sleeve and spindle, thepassageway being adapted to capture the end of the hookup lead.

3. A dual wire wrapping head for interconnecting terminals with ameasured length of hookup lead, comprising a pair of bits, each bithaving means formed therein for receiving a terminal, meanscommunicating with the receiving means for guiding hookup lead onto theterminal, and a guide slot passing transversely through the bit forreceiving and for fully encompassing a length of hookup lead, and

means for projecting a length of hookup lead through the guide slots,for measuring and severing the length of hookup lead within the slots tothe measured length in preparation for interconnecting the terminalswith the measured length of hookup lead.

4. A [dual] wire wrapping head having a [pair of bits] bit for wrappingthe end[s] of a measured length of hookup lead onto a [pair of spaced]terminal[s, each bit] comprising a spindle having a bore for receiving aterminal and an external groove extending longitudinally from the tip ofthe spindle, the spindle also having a [transverse] guide slot formedtransversely to the longitudinal axis of the spindle through the spindleand terminating in the other end of the groove for receiving andcompletely encompassing the hookup lead to maintain the hookup lead in apredetermined position prior to wrapping, and

a sleeve slidably mounted over the spindle and having an internal,longitudinally extending passage aligned with the groove of the spindle,the passage and groove defining a guideway for guiding the hookup leadduring the wrapping of the terminal.

5. A [dual] wire wrapping head having a [pair of] bit[s] for wrappingthe bare end [5] of a measured length of hookup lead made up of aninsulated wire strand onto a pair of spindles, each spindle having abore for rea [pair of spaced] terminal[s, each bit] comprising ceiving aterminal and an external, longitudinally a spindle having a guide slotformed transversely t the longitudinal axis of the spindle through thespindle for receiving and for fully encompassing the lead to maintainthe lead in a predetermined position prior to wrapping about a terminal,the spindle having an external groove extending longitudinally from thetip of the spindle and terminating in the guide slot, the spindle havinga cutting edge formed at the extending groove formed in the spindle withone end of the groove curling over the tip of the spindle to intersectthe bore, the spindle also having a transverse guide slot formed throughthe spindle and terminating in the other end of the groove for receivingand completely encompassing the hookup lead to maintain the hookup leadin a predetermined position prior to wrapping,

end of the groove terminating in the guide slot, and 10 a pair ofsleeves, each sleeve slidably mounted over a sleeve slidably mountedover the spindle having an one spindle and having an elongated passagealigned internal longitudinally extending passage which interwith thegroove of the spindle, the passage and sects the end of the sleeve todefine a cutting edge, groove defining a guideway for guiding the endthe cutting edges of the sleeve and spindle being cof the hookup leadduring the wrapping of the operable to peripherally sever only theinsulation terminal hollow needle-like tube projectable through at apredetermined distance from an end of the lead, n g ide lot to carryhookup lead through the the groove and passage together defining aguideway guide slots, substantially equal in diameter to the diameter ofa hollow (idle-like tube pfoleflable through one the bare end of thelead. guide slot to carry hookup lead through the guide slots, means forprojecting the needle-like tube with the hookup lead through one guideslot and for retracting only the needle-like tube from the guide slots,and

cutting means for severing the hookup lead to the measured length afterthe needle-like tube has been retracted from the guide slot. 9. A wirewrapping head having a bit for wrapping the end of a wire onto aterminal, comprising:

a spindle having a longitudinal bore in one end for 6. A dual wirewrapping head for interconnecting terminals with hookup lead made up ofan insulated wire strand including a pair of wrapping bits, each bitcomprising an elongated sleeve having an internal, longitudinallyextending passage formed therein which intersects the tip portion of thesleeve to define a first cutting edge, and

a spindle slidably mounted within the sleeve and having means thereonfor receiving a terminal and means for guiding wire strand about theterminal, the

spindle having an elongated longitudinally extending guide slot passingtransversely therethrough, the guide slot defining an opening nearestthe tip of the spindle receiving a terminal and a guide slot formedtransversely to the longitudinal axis of the spindle through the spindlefor receiving the end of the wire;

substantiany 6qua] in diameter to the diameter f a sleeve slidah'lymounted on the spindle such that one the Wire strand, the spindle havingan external, longiend of the sleeve slides over the transverse slot totudinally formed groove which extends from the tip the One and f [hfspindlfiand f the Spindle to intersect the Opening to d fa alongitudinal passageway formed between the spindle second cutting edgecooperable with the first cutting 40 and sleeve f the transvelse to theOne end edge to shear only the insulation of the hookup lead, the grooveand passage together defining a guideway substantially equal in diameterto the diameter of of the spindle and one end of the sleeve forcapturing the end of the wire when t e one end of the sleeve slides overthe transverse slot to the one end of the spindle. 10. A wire wrappinghead having a bit for wrapping the end of a wire onto a terminal, asdefined in claim 9,

wherein:

the transvdrse guide slot tapers to provide a connection between theguide slot and passageway.

the wire strand.

7. In a [dual] wrapping head for wrapping the bare end[s] of a measuredlength of [hookup lead made of] an insulated wire strand onto a [pair ofspaced] terminal[s] a [pair of] bit[s, each bit] comprising an elongatedsleeve having an internal, longitudinally extending passage formedtherein, and

an elongated spindle mounted for slidable movement within the sleeve andhaving a guide slot formed longitudinally in and passing transverselythrough the axis of the spindle for completely encompassing ReferencesCited The following references, cited by the Examiner, are of record inthe patented file of this patent or the original atent.

and maintaining the hookup lead in a predetermined p UNITED STATESPATENTS positlon prior to wrapplng a bare end about a terminal, thespindle having an external, longitudinally 2,632,063 6/1954 M he 7-14.1extending groove cooperable with the passage to 2|696,656 12/1954 Madden29-33 define a guideway of a diameter substantially equal 2,743,5025/1956 R k 29-33 to the diameter of the wire strand for maintaining2,746,124 5/1956 Belek 242-7 X the wire strand in a longitudinal path,the spindle 2,807,810 10/1957 Belfik et 714.1 having a neck portion fordirecting the hookup lead 3,191,379 6955 Allen 29-203 from the slot tothe guideway, the spindle also hav- 3,213,894 10/1955 EtChiIlSOn t 1...l 242-703 ing means for receiving a terminal and means for guiding thewire strand from the guideway onto a terminal. 8. An apparatus forWrapping the ends of a measured length of hookup lead onto a pair ofspaced terminals, comprising THOMAS H. EAGER, Primary Examiner US. Cl.X.R.

